pdns specific as packaged in Debian in version before 3.3.1-1 creates a too privileged MySQL user. It was discovered that the maintainer scripts of pdns-backend-mysql grant too wide database permissions for the pdns user. Other backends
are not affected.
In the Linux kernel, the following vulnerability has been resolved:
net_sched: prio: fix a race in prio_tune()
Gerrard Tai reported a race condition in PRIO, whenever SFQ perturb timer
fires at the wrong time.
The race is as follows:
CPU 0 CPU 1
[1]: lock root
[2]: qdisc_tree_flush_backlog()
[3]: unlock root
|
| [5]: lock root
| [6]: rehash
| [7]: qdisc_tree_reduce_backlog()
|
[4]: qdisc_put()
This can be abused to underflow a parent's qlen.
Calling qdisc_purge_queue() instead of qdisc_tree_flush_backlog()
should fix the race, because all packets will be purged from the qdisc
before releasing the lock.
In the Linux kernel, the following vulnerability has been resolved:
platform/x86: dell-wmi-sysman: Avoid buffer overflow in current_password_store()
If the 'buf' array received from the user contains an empty string, the
'length' variable will be zero. Accessing the 'buf' array element with
index 'length - 1' will result in a buffer overflow.
Add a check for an empty string.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
In the Linux kernel, the following vulnerability has been resolved:
ALSA: pcm: Fix race of buffer access at PCM OSS layer
The PCM OSS layer tries to clear the buffer with the silence data at
initialization (or reconfiguration) of a stream with the explicit call
of snd_pcm_format_set_silence() with runtime->dma_area. But this may
lead to a UAF because the accessed runtime->dma_area might be freed
concurrently, as it's performed outside the PCM ops.
For avoiding it, move the code into the PCM core and perform it inside
the buffer access lock, so that it won't be changed during the
operation.
In the Linux kernel, the following vulnerability has been resolved:
crypto: algif_hash - fix double free in hash_accept
If accept(2) is called on socket type algif_hash with
MSG_MORE flag set and crypto_ahash_import fails,
sk2 is freed. However, it is also freed in af_alg_release,
leading to slab-use-after-free error.
In the Linux kernel, the following vulnerability has been resolved:
x86/mm: Check return value from memblock_phys_alloc_range()
At least with CONFIG_PHYSICAL_START=0x100000, if there is < 4 MiB of
contiguous free memory available at this point, the kernel will crash
and burn because memblock_phys_alloc_range() returns 0 on failure,
which leads memblock_phys_free() to throw the first 4 MiB of physical
memory to the wolves.
At a minimum it should fail gracefully with a meaningful diagnostic,
but in fact everything seems to work fine without the weird reserve
allocation.
In the Linux kernel, the following vulnerability has been resolved:
libnvdimm/labels: Fix divide error in nd_label_data_init()
If a faulty CXL memory device returns a broken zero LSA size in its
memory device information (Identify Memory Device (Opcode 4000h), CXL
spec. 3.1, 8.2.9.9.1.1), a divide error occurs in the libnvdimm
driver:
Oops: divide error: 0000 [#1] PREEMPT SMP NOPTI
RIP: 0010:nd_label_data_init+0x10e/0x800 [libnvdimm]
Code and flow:
1) CXL Command 4000h returns LSA size = 0
2) config_size is assigned to zero LSA size (CXL pmem driver):
drivers/cxl/pmem.c: .config_size = mds->lsa_size,
3) max_xfer is set to zero (nvdimm driver):
drivers/nvdimm/label.c: max_xfer = min_t(size_t, ndd->nsarea.max_xfer, config_size);
4) A subsequent DIV_ROUND_UP() causes a division by zero:
drivers/nvdimm/label.c: /* Make our initial read size a multiple of max_xfer size */
drivers/nvdimm/label.c: read_size = min(DIV_ROUND_UP(read_size, max_xfer) * max_xfer,
drivers/nvdimm/label.c- config_size);
Fix this by checking the config size parameter by extending an
existing check.
In the Linux kernel, the following vulnerability has been resolved:
vhost-scsi: protect vq->log_used with vq->mutex
The vhost-scsi completion path may access vq->log_base when vq->log_used is
already set to false.
vhost-thread QEMU-thread
vhost_scsi_complete_cmd_work()
-> vhost_add_used()
-> vhost_add_used_n()
if (unlikely(vq->log_used))
QEMU disables vq->log_used
via VHOST_SET_VRING_ADDR.
mutex_lock(&vq->mutex);
vq->log_used = false now!
mutex_unlock(&vq->mutex);
QEMU gfree(vq->log_base)
log_used()
-> log_write(vq->log_base)
Assuming the VMM is QEMU. The vq->log_base is from QEMU userpace and can be
reclaimed via gfree(). As a result, this causes invalid memory writes to
QEMU userspace.
The control queue path has the same issue.
In the Linux kernel, the following vulnerability has been resolved:
scsi: target: iscsi: Fix timeout on deleted connection
NOPIN response timer may expire on a deleted connection and crash with
such logs:
Did not receive response to NOPIN on CID: 0, failing connection for I_T Nexus (null),i,0x00023d000125,iqn.2017-01.com.iscsi.target,t,0x3d
BUG: Kernel NULL pointer dereference on read at 0x00000000
NIP strlcpy+0x8/0xb0
LR iscsit_fill_cxn_timeout_err_stats+0x5c/0xc0 [iscsi_target_mod]
Call Trace:
iscsit_handle_nopin_response_timeout+0xfc/0x120 [iscsi_target_mod]
call_timer_fn+0x58/0x1f0
run_timer_softirq+0x740/0x860
__do_softirq+0x16c/0x420
irq_exit+0x188/0x1c0
timer_interrupt+0x184/0x410
That is because nopin response timer may be re-started on nopin timer
expiration.
Stop nopin timer before stopping the nopin response timer to be sure
that no one of them will be re-started.
In the Linux kernel, the following vulnerability has been resolved:
genirq/msi: Store the IOMMU IOVA directly in msi_desc instead of iommu_cookie
The IOMMU translation for MSI message addresses has been a 2-step process,
separated in time:
1) iommu_dma_prepare_msi(): A cookie pointer containing the IOVA address
is stored in the MSI descriptor when an MSI interrupt is allocated.
2) iommu_dma_compose_msi_msg(): this cookie pointer is used to compute a
translated message address.
This has an inherent lifetime problem for the pointer stored in the cookie
that must remain valid between the two steps. However, there is no locking
at the irq layer that helps protect the lifetime. Today, this works under
the assumption that the iommu domain is not changed while MSI interrupts
being programmed. This is true for normal DMA API users within the kernel,
as the iommu domain is attached before the driver is probed and cannot be
changed while a driver is attached.
Classic VFIO type1 also prevented changing the iommu domain while VFIO was
running as it does not support changing the "container" after starting up.
However, iommufd has improved this so that the iommu domain can be changed
during VFIO operation. This potentially allows userspace to directly race
VFIO_DEVICE_ATTACH_IOMMUFD_PT (which calls iommu_attach_group()) and
VFIO_DEVICE_SET_IRQS (which calls into iommu_dma_compose_msi_msg()).
This potentially causes both the cookie pointer and the unlocked call to
iommu_get_domain_for_dev() on the MSI translation path to become UAFs.
Fix the MSI cookie UAF by removing the cookie pointer. The translated IOVA
address is already known during iommu_dma_prepare_msi() and cannot change.
Thus, it can simply be stored as an integer in the MSI descriptor.
The other UAF related to iommu_get_domain_for_dev() will be addressed in
patch "iommu: Make iommu_dma_prepare_msi() into a generic operation" by
using the IOMMU group mutex.